The primary objectives of this project are to elucidate the epidemiology of American (New World) visceral leishmaniasis (AVL) and to develop novel methods for its control. The project will involve both field and laboratory studies. Field work on the project will be carried out in Colombia, South American in an area where AVL is hyperendemic. Field work during the first two years of the project will focus on the biology of the sand fly vector (Lutzomyia longipalpis) and on the role of domestic and wild animals as reservoirs of the parasite (Leishmania chagasi). Laboratory studies during the initial two years will include the following: (1) an evaluation of the opossum, Didelphia marsupialis, as a periodomestic reservoir of L. chagasi, (2) a comparison of serologic techniques for the diagnosis of L. chagasi infection in animals, and (3) the development of novel methods for sand fly control. The second two years of the project will be devoted to an actual field evaluation of the feasibility and results of these techniques in controlling the transmission of L. chagasi in the endemic area. The proposed project is of four years duration and involves the fields of parasitology, medical entomology, epidemiology and public health.